1 /*
2  * Copyright (c) 2004 Topspin Communications.  All rights reserved.
3  *
4  * This software is available to you under a choice of one of two
5  * licenses.  You may choose to be licensed under the terms of the GNU
6  * General Public License (GPL) Version 2, available from the file
7  * COPYING in the main directory of this source tree, or the
8  * OpenIB.org BSD license below:
9  *
10  *     Redistribution and use in source and binary forms, with or
11  *     without modification, are permitted provided that the following
12  *     conditions are met:
13  *
14  *      - Redistributions of source code must retain the above
15  *        copyright notice, this list of conditions and the following
16  *        disclaimer.
17  *
18  *      - Redistributions in binary form must reproduce the above
19  *        copyright notice, this list of conditions and the following
20  *        disclaimer in the documentation and/or other materials
21  *        provided with the distribution.
22  *
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30  * SOFTWARE.
31  *
32  * $Id: mthca_reset.c 1349 2004-12-16 21:09:43Z roland $
33  */
34 
35 #include <linux/init.h>
36 #include <linux/errno.h>
37 #include <linux/pci.h>
38 #include <linux/delay.h>
39 #include <linux/slab.h>
40 
41 #include "mthca_dev.h"
42 #include "mthca_cmd.h"
43 
44 int mthca_reset(struct mthca_dev *mdev)
45 {
46 	int i;
47 	int err = 0;
48 	u32 *hca_header    = NULL;
49 	u32 *bridge_header = NULL;
50 	struct pci_dev *bridge = NULL;
51 	int bridge_pcix_cap = 0;
52 	int hca_pcie_cap = 0;
53 	int hca_pcix_cap = 0;
54 
55 	u16 devctl;
56 	u16 linkctl;
57 
58 #define MTHCA_RESET_OFFSET 0xf0010
59 #define MTHCA_RESET_VALUE  swab32(1)
60 
61 	/*
62 	 * Reset the chip.  This is somewhat ugly because we have to
63 	 * save off the PCI header before reset and then restore it
64 	 * after the chip reboots.  We skip config space offsets 22
65 	 * and 23 since those have a special meaning.
66 	 *
67 	 * To make matters worse, for Tavor (PCI-X HCA) we have to
68 	 * find the associated bridge device and save off its PCI
69 	 * header as well.
70 	 */
71 
72 	if (!(mdev->mthca_flags & MTHCA_FLAG_PCIE)) {
73 		/* Look for the bridge -- its device ID will be 2 more
74 		   than HCA's device ID. */
75 		while ((bridge = pci_get_device(mdev->pdev->vendor,
76 						mdev->pdev->device + 2,
77 						bridge)) != NULL) {
78 			if (bridge->hdr_type    == PCI_HEADER_TYPE_BRIDGE &&
79 			    bridge->subordinate == mdev->pdev->bus) {
80 				mthca_dbg(mdev, "Found bridge: %s\n",
81 					  pci_name(bridge));
82 				break;
83 			}
84 		}
85 
86 		if (!bridge) {
87 			/*
88 			 * Didn't find a bridge for a Tavor device --
89 			 * assume we're in no-bridge mode and hope for
90 			 * the best.
91 			 */
92 			mthca_warn(mdev, "No bridge found for %s\n",
93 				  pci_name(mdev->pdev));
94 		}
95 
96 	}
97 
98 	/* For Arbel do we need to save off the full 4K PCI Express header?? */
99 	hca_header = kmalloc(256, GFP_KERNEL);
100 	if (!hca_header) {
101 		err = -ENOMEM;
102 		mthca_err(mdev, "Couldn't allocate memory to save HCA "
103 			  "PCI header, aborting.\n");
104 		goto out;
105 	}
106 
107 	for (i = 0; i < 64; ++i) {
108 		if (i == 22 || i == 23)
109 			continue;
110 		if (pci_read_config_dword(mdev->pdev, i * 4, hca_header + i)) {
111 			err = -ENODEV;
112 			mthca_err(mdev, "Couldn't save HCA "
113 				  "PCI header, aborting.\n");
114 			goto out;
115 		}
116 	}
117 
118 	hca_pcix_cap = pci_find_capability(mdev->pdev, PCI_CAP_ID_PCIX);
119 	hca_pcie_cap = pci_find_capability(mdev->pdev, PCI_CAP_ID_EXP);
120 
121 	if (bridge) {
122 		bridge_header = kmalloc(256, GFP_KERNEL);
123 		if (!bridge_header) {
124 			err = -ENOMEM;
125 			mthca_err(mdev, "Couldn't allocate memory to save HCA "
126 				  "bridge PCI header, aborting.\n");
127 			goto out;
128 		}
129 
130 		for (i = 0; i < 64; ++i) {
131 			if (i == 22 || i == 23)
132 				continue;
133 			if (pci_read_config_dword(bridge, i * 4, bridge_header + i)) {
134 				err = -ENODEV;
135 				mthca_err(mdev, "Couldn't save HCA bridge "
136 					  "PCI header, aborting.\n");
137 				goto out;
138 			}
139 		}
140 		bridge_pcix_cap = pci_find_capability(bridge, PCI_CAP_ID_PCIX);
141 		if (!bridge_pcix_cap) {
142 				err = -ENODEV;
143 				mthca_err(mdev, "Couldn't locate HCA bridge "
144 					  "PCI-X capability, aborting.\n");
145 				goto out;
146 		}
147 	}
148 
149 	/* actually hit reset */
150 	{
151 		void __iomem *reset = ioremap(pci_resource_start(mdev->pdev, 0) +
152 					      MTHCA_RESET_OFFSET, 4);
153 
154 		if (!reset) {
155 			err = -ENOMEM;
156 			mthca_err(mdev, "Couldn't map HCA reset register, "
157 				  "aborting.\n");
158 			goto out;
159 		}
160 
161 		writel(MTHCA_RESET_VALUE, reset);
162 		iounmap(reset);
163 	}
164 
165 	/* Docs say to wait one second before accessing device */
166 	msleep(1000);
167 
168 	/* Now wait for PCI device to start responding again */
169 	{
170 		u32 v;
171 		int c = 0;
172 
173 		for (c = 0; c < 100; ++c) {
174 			if (pci_read_config_dword(bridge ? bridge : mdev->pdev, 0, &v)) {
175 				err = -ENODEV;
176 				mthca_err(mdev, "Couldn't access HCA after reset, "
177 					  "aborting.\n");
178 				goto out;
179 			}
180 
181 			if (v != 0xffffffff)
182 				goto good;
183 
184 			msleep(100);
185 		}
186 
187 		err = -ENODEV;
188 		mthca_err(mdev, "PCI device did not come back after reset, "
189 			  "aborting.\n");
190 		goto out;
191 	}
192 
193 good:
194 	/* Now restore the PCI headers */
195 	if (bridge) {
196 		if (pci_write_config_dword(bridge, bridge_pcix_cap + 0x8,
197 				 bridge_header[(bridge_pcix_cap + 0x8) / 4])) {
198 			err = -ENODEV;
199 			mthca_err(mdev, "Couldn't restore HCA bridge Upstream "
200 				  "split transaction control, aborting.\n");
201 			goto out;
202 		}
203 		if (pci_write_config_dword(bridge, bridge_pcix_cap + 0xc,
204 				 bridge_header[(bridge_pcix_cap + 0xc) / 4])) {
205 			err = -ENODEV;
206 			mthca_err(mdev, "Couldn't restore HCA bridge Downstream "
207 				  "split transaction control, aborting.\n");
208 			goto out;
209 		}
210 		/*
211 		 * Bridge control register is at 0x3e, so we'll
212 		 * naturally restore it last in this loop.
213 		 */
214 		for (i = 0; i < 16; ++i) {
215 			if (i * 4 == PCI_COMMAND)
216 				continue;
217 
218 			if (pci_write_config_dword(bridge, i * 4, bridge_header[i])) {
219 				err = -ENODEV;
220 				mthca_err(mdev, "Couldn't restore HCA bridge reg %x, "
221 					  "aborting.\n", i);
222 				goto out;
223 			}
224 		}
225 
226 		if (pci_write_config_dword(bridge, PCI_COMMAND,
227 					   bridge_header[PCI_COMMAND / 4])) {
228 			err = -ENODEV;
229 			mthca_err(mdev, "Couldn't restore HCA bridge COMMAND, "
230 				  "aborting.\n");
231 			goto out;
232 		}
233 	}
234 
235 	if (hca_pcix_cap) {
236 		if (pci_write_config_dword(mdev->pdev, hca_pcix_cap,
237 				 hca_header[hca_pcix_cap / 4])) {
238 			err = -ENODEV;
239 			mthca_err(mdev, "Couldn't restore HCA PCI-X "
240 				  "command register, aborting.\n");
241 			goto out;
242 		}
243 	}
244 
245 	if (hca_pcie_cap) {
246 		devctl = hca_header[(hca_pcie_cap + PCI_EXP_DEVCTL) / 4];
247 		if (pci_write_config_word(mdev->pdev, hca_pcie_cap + PCI_EXP_DEVCTL,
248 					   devctl)) {
249 			err = -ENODEV;
250 			mthca_err(mdev, "Couldn't restore HCA PCI Express "
251 				  "Device Control register, aborting.\n");
252 			goto out;
253 		}
254 		linkctl = hca_header[(hca_pcie_cap + PCI_EXP_LNKCTL) / 4];
255 		if (pci_write_config_word(mdev->pdev, hca_pcie_cap + PCI_EXP_LNKCTL,
256 					   linkctl)) {
257 			err = -ENODEV;
258 			mthca_err(mdev, "Couldn't restore HCA PCI Express "
259 				  "Link control register, aborting.\n");
260 			goto out;
261 		}
262 	}
263 
264 	for (i = 0; i < 16; ++i) {
265 		if (i * 4 == PCI_COMMAND)
266 			continue;
267 
268 		if (pci_write_config_dword(mdev->pdev, i * 4, hca_header[i])) {
269 			err = -ENODEV;
270 			mthca_err(mdev, "Couldn't restore HCA reg %x, "
271 				  "aborting.\n", i);
272 			goto out;
273 		}
274 	}
275 
276 	if (pci_write_config_dword(mdev->pdev, PCI_COMMAND,
277 				   hca_header[PCI_COMMAND / 4])) {
278 		err = -ENODEV;
279 		mthca_err(mdev, "Couldn't restore HCA COMMAND, "
280 			  "aborting.\n");
281 		goto out;
282 	}
283 
284 out:
285 	if (bridge)
286 		pci_dev_put(bridge);
287 	kfree(bridge_header);
288 	kfree(hca_header);
289 
290 	return err;
291 }
292